Under the Internal Revenue Code, all section 501(c)(3) organizations are absolutely prohibited from directly or indirectly participating in, or intervening in, any political campaign on behalf of (or in opposition to) any candidate for elective public office. The prohibition applies to all campaigns including campaigns at the federal, state and local level. Violation of this prohibition may result in denial or revocation of tax-exempt status and the imposition of certain excise taxes.

and

Allowing a candidate to use an organization’s assets or facilities will also violate the prohibition if other candidates are not given an equivalent opportunity.